This paper studies the factors driving changes in judicial independence (JI) as incorporated in constitutions. Two indicators of constitutionally safeguarded JI are constructed. Variations in these indicators are identified based on changes in the constitutions of as many as 100 countries that occurred between 1950 and 2005. Four groups of factors are conjectured to be relevant for explaining these changes. We find only weak evidence for the insurance theory of judicial independence but strong evidence that the characteristics of individual leaders - such as how they acquired or lost power - play an important role in explaining changes in constitutionally safeguarded JI. This paper contributes not only to the literature on JI but also to the theory of endogenous constitutions.